The foreman should never be authorized to enforce his discipline with the whip if he can accomplish his result with words. Avoid having many slaves of the same nation, for this gives rise to domestic rows. The foremen will work more cheerfully if rewards are offered them, and particularly pains must be taken to see that they have some property of their own, and that they marry wives among their fellow servants, who may bear them children, some thing which will make them more steady and attach them to the place.[75] On account of such relationships families of Epirote slaves are esteemed the best and command the highest prices. Marks of consideration by the master will go far in giving happiness to your hands: as, for instance, by asking the opinion of those of them who have done good work, as to how the work ought to be done, which has the effect of making them think less that they are looked down upon, and encourages them to believe that they are held in some estimation by the master. Those slaves who are most attentive to their work should be treated more liberally either in respect of food or clothes, or in holidays, or by giving them permission to graze some cattle of their own on the place, or some thing of that kind. Such liberality tempers the effect of a harsh order or a heavy punishment, and restores the slaves' good will and kindly feeling towards their master. XVIII. On the subject of the number of slaves one will require for operating a farm, Cato lays down the two measures of the extent of the farm and the kind of farming to be carried on. Writing about the cultivation of olives and vines he gives these formulas, viz.: For carrying on an olive farm of two hundred and forty jugera, thirteen slaves are necessary, to-wit: an overseer, a housekeeper, five labourers, three teamsters, an ass driver, a swineherd and a shepherd: for carrying on a vineyard of one hundred jugera, fifteen slaves are necessary, to-wit: an overseer, a housekeeper, ten labourers, a teamster, an ass driver and a swineherd. On the other hand Saserna says that one man is enough for every eight jugera,[76] as a man should cultivate that much land in forty-five days: for while one man can cultivate a jugerum in four days, yet he allows thirteen days extra for the entire eight jugera to provide against the chance of bad weather, the illness or idleness of the labourer and the indulgence of the master.[77] At this Licinius Stolo put in.